Kinematic Orbit Positioning Applying the Raw Observation Approach

Abstract:

Determining Earth’s gravity field variations by means of precise positions of low-earth orbiting (LEO) satellites is a suitable supplementary method beside to the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On satellite missions. Precise orbit determination done via the kinematic strategy uses only geometric observations to estimate the satellite orbit and neglects the consideration of any forces. This strategy requires a large amount of observation data for each epoch to determine the three-dimensional satellite position. The usage of the spaceborne global navigation satellite system technology offers the opportunity to get high accurate observation data. Following Zehentner (2016) the kinematic orbit positioning by applying the raw observation approach using a least-squares adjustment has shown promising results with a high accuracy. An improvement of the approach could be achieved by taking into account, for example, enhanced models of non-conservative forces, the introduction of macro models and a more accurate antenna center variation estimation. In our current work we are estimating the kinematic orbits for several LEO satellite missions by using the refined approach and subsequently validating them by a comparison with state-of-the-art gravity field solutions.